package com.example.dqnm.utils;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.interfaces.DecodedJWT;
import com.example.dqnm.pojo.User;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * @author zm
 * @desc 使用token验证用户是否登录
 **/
public class TokenUtils {
    //设置过期时间
    private static final long EXPIRE_DATE = 30 * 60 * 100000;
    //token秘钥
    private static final String TOKEN_SECRET = "theKey";

    public static String token(User user) {
        String token = "";
        try {
            //过期时间
            Date date = new Date(System.currentTimeMillis() + EXPIRE_DATE);
            //秘钥及加密算法
            Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET);
            //设置头部信息
            Map<String, Object> header = new HashMap<>();
            header.put("typ", "JWT");
            header.put("alg", "HS256");
            //携带openid, headimageUrl, nickname信息，生成签名
            token = JWT.create()
                    .withHeader(header)
                    .withClaim("openid", user.getOpenid())
                    .withClaim("headimageUrl", user.getHeadimageurl())
                    .withClaim("nickname", user.getNickname())
                    .withExpiresAt(date)
                    .sign(algorithm);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        return token;
    }

    public static boolean verify(String token) {
        /**
         * @desc 验证token，通过返回true
         * @params [token]需要校验的串
         **/
        try {
            Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET);
            JWTVerifier verifier = JWT.require(algorithm).build();
            DecodedJWT jwt = verifier.verify(token);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public static String getOpenId(String token) {
        Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET);
        JWTVerifier verifier = JWT.require(algorithm).build();
        DecodedJWT jwt = verifier.verify(token);
        String openid =  jwt.getClaim("openid").toString();
        return openid.substring(1, openid.length() - 1);
    }
}
